Manufacture of corrugated board



Nov. 10, 1942. J GILUAN 2,301,695

MANUFACTURE OF CORRUGATED BOARD Filed Oct. 25, 1939 Iruf e FEW lose W2.Zozgk 01/4022 Patented Nov. 10, 1942 2,301,695 MANUFACTURE orCORRUGATED BOARD -Joseph Louis Gillian, Milwaukee, Wisf, assignor toCorn Products Refining Company, New York, N. Y., a corporation of NewJersey Application October 25, 1939, Serial No. 301,187

'4Claims.

This invention relates to the manufacture of lined corrugated paperboard and the object of the invention is to provide an improvement onthe known apparatus for making corrugated paper board whereby thequality of the product is improved, the speed of production isincreased, the amount of waste is reduced, and less adhesive material isemployed.

In the manufacture of lined corrugated paper board it is important thatthe amount of paste employed for securing the liner to the corrugatedboard be neither too great nor too small. If the amount be too great thepaste consumption is unnecessarily increased; the time required for thebond to set is increased; and the moisture content of the product isincreased thereby tending to reduce the desired stiffness of theproduct. If the amount be too small the bond, of course, is not obtainedand factory wastage increases.

It has heretofore been customary to apply paste to the ridges of thecorrugated sheet by means of a doctor roll or transfer roll to which thepaste is fed from the surface of an adjacent, power driven roll, thelower portion of which latter roll extends below the surface of a bodyof paste maintained in a paste pan. This expedient, whi-le widely usedwith relative success, does not apply the adhesive with the desireddegree of uniformity. That is to say, some of the ridges are overloadedwith paste while others have an insuflicient amount. This undesirablecondition is especially noted when a relatively thick paste is employedas the adhesive. If a ridge, or any portion thereof, receives aninsufllcient amount of adhesive an unsatisfactory bond will result. Onthe other hand, if a ridge, or any portion thereof, is overloaded withpaste the excess paste will be forced into the adjacent grooves of thecorrugated sheet, resulting not only in paste wastage but also increasedmoisture content and weight of the finished board (which is undesirable)and increased bonding time, which slows up the process.

The present invention comprises in brief, the

provision of means for distributing the adhesive uniformly over theridges of the corrugated sheet after the adhesive has been applied bythe doctor roll or transfer roll which distributing means, in thepreferred embodiment of the invention, consists of a paste spreadingroll over which the pasted ridges of the corrugated sheet pass after thepaste has been applied thereto. This spreading/ roll, which may be powerdriven but preferthe frictional engagement of the corrugated boardtherewith, serves not only to distribute the previously applied paste ina thin, uniform film over the ridges but also removes any excess pastewithout permitting the paste to contact the adjacent grooves of thecorrugated sheet.

An idle roll is preferred (that is, a roll which is driven solely by thecorrugated sheet frictionally engaging the periphery thereof) for thereason that the peripheral speed of an idle roll so actuated mustnecessarily be no greater than the speed of movement of the corrugatedsheet itself. Such roll will, therefore, respond immediately to anyreduction, increase, or interruption in. the movement of the corrugatedsheet and, therefore, the excess paste will be removed without beingforced into the grooves of the sheet. As above noted, the presence ofexcess paste in the grooves would not only waste paste but would alsoundesirably increase the moisture content of the finished product anddecrease the speed of production. If a power driven roll is used careshould be taken to have the peripheral speed of the roll the same as thespeed of the corrugated sheet to avoid the undesired consequences abovenoted.

ably is an idle roll which rotates responsive to The invention isillustrated more or less diagrammatically in the accompanying drawingwherein the present invention is illustrated as applied to the doubleback paster of the conventional corrugated machine. Referring to thedrawing, the straw-board or other suitable material, designated byreference character lll, passes through the conventional corrugatingrolls H, II; paste is applied to the ridges by means of pasting rolls[3, H, the latter of which-draws paste from paste pan 15; the singleback liner i6 is applied thereto at H; and the material passes oversuitable guide rolls and heating rolls to the double back unit fprapplication of a liner to the opposite side of the corrugated sheet.

The double back unit comprises the conventional guide table l8, pastepan l9, paste roll 20, transfer roll 2|, and pressure roll 22. The pasteis applied to the corrugated sheet by transfer roll 2|. The double backliner sheet 23, which is preferably pre-heated in steam chest 24, issupplied to the pasted ridges of the corrugated sheet at point 25.

The paste distributing means which, in combination with the knownmechanism above described. constitutes the present invention, is illus-;trated by reference character 26, and, as above stated, preferably,consists of an idle roll mounted to be engaged "by the ridges of thecorrugated sheet and to rotate responsive to such engagement. in thedirection indicated by the arrow. Preferably the paste spreading roll 26is not less than approximately two inches in diameter and is mounted sothat its point of contact with the corrugated sheet is between four andonehalf and five inches from the point of application of the pastethereto by the transfer roll 2|. Generally speaking the precise locationof the .spreading roll will be governed by the type of adhesive employedand the speed of the machine and it will be understood, therefore, thatthe above figures are merely suggestive and not by way of limitation.Also it is preferred to mount the spreading roll 26 so that any excesspaste removed thereby will fall back into the paste pan iii.

The spreading roll 26 serves not only to distribute the paste uniformlyover the ridges of the fiutings (which results in a better bond) butalso reduces the paste consumption, increases the speed of the machine(because a quicker bond is obtained) and improves the quality ofthe-product for the'reason that the removal of excess paste reduces itsweight and moisture content,

As illustrative of the advantages obtained by the present invention itis noted that with the provision of a spreading roll of the type abovedescribed the amount of adhesive employed (a modified corn starchpaste)was reduced from three to two and one-half pounds per thousand squarefeet; the board was stiffer; the speed of the machine was increasedabout fifteen feet per minute; and the wastage was decreased by nearlyIt is the intention to cover all modifications within the scope of thefollowing claims.

I claim:

1. In an apparatus for continuously pasting a liner to acorrugated'sheet comprising a paste applicator, means for continuouslypassing an unlined side of a corrugated sheet across the pasteapplicator for application of paste to the ridges of the sheet, andmeans'for continuously applying a liner to the pasted ridges, theimprovement which consists of a paste spreading roll mounted for freerotation around its longitudinal axis between the paste applicator andthe liner applying means and positioned to be engaged and rotated by thepasted ridges of the corrugated sheet, whereby'paste is evenly anduniformly distributed over the surface of said ridges and. excess pasteis removed from the "sheet.

applicator, means for continuously passing an unlined side of acorrugated sheet across the paste applicator for application of paste tothe ridges of the sheet, and means for continuously applying a liner tothe pasted ridges, the improvement which consists of a paste spreadingroll mounted for rotation around its longitudinal axis between the pasteapplicator and the liner applying means and so positioned that theperiphery thereof will engage the pasted ridges of the corrugated sheet,will evenly'and' uniformly distribute the desired amount of paste overthe surface of said ridges and will remove excess paste from the sheet,the peripheral speed of the paste spreading roll being the same as thelinear speed of the corrugated sheet.

3. In an apparatus for continuously pasting a liner to the ridges of acorrugated sheet comprising means for continuously applying paste from asource of supply to the ridges of a corrugated sheet and means forcontinuously applying a liner to said pasted ridges, the. improvementwhich consists in the .provision of means having a surface engaging, andmoving at the same linear speed as the pasted ridges of the corrugatedsheet for distributingthe paste over the surface of said ridges andremoving any excess paste from the sheet.

4. In an apparatus for continuously pasting a liner to the ridges of acorrugated sheet comprising means for continuously applying paste from asource of supply to the ridges of a corrugated sheet and means forcontinuously ap plying a liner to said pasted ridges, the improve-' mentwhich consists in the provision of means having a surface engaging. andmoving at the same linear speed as the pasted ridges of the corrugatedsheet for distributing the paste over the surface of said ridges,removing any excess from the sheet and returning such excess to thesource of paste supply.

JOSEPH LOUIS GILLIAN.

Palteqt No; 2,501,695;

" foiii, to the record'of the case 1:; the Patent Office.

--- dE1i'rIF1cA TE oF com? EON.

' Novmber 10,. 1914.2.

- JOSEPH LOUIS It 1-8 herebyjcertified thgt error appears in the printedspecification Li -f1 the'above numbere d p at ent "requiring cor rectionas follovqs: Paige 2,1 first I co1umn,'line 20', for "f1utings"' readsheetahd the said Letters gateglt sh'ould be read with this corr'ecti ontherein that the nm' con sighed 9 5d sealed this 29th day of Decembe-QA. 1). 191m.

v Henry Van' Arsdale (Seal) Aetlngcommissionerpf Patents.

